File Size AP vs PS?

[OldHickory30]

Curious, why would there be such a  size difference after exporting from Photoshop, compared to Affinity? Seems that PS is always 40-90% larger. I processed two files 16bit w/ no extra layers, a tiff - native size. PS was 1.9gb and Affinity 1.08gb Thats almost a gig in difference. I've tried other configurations, same thing, PS is always much way larger with no compression. Feels like I'm loosing something in Affinity or PS is adding something within the algorithm. After 20+ years of using PS, I'm not a fan, but I am curious. 

[R C-R]

13 minutes ago, OldHickory30 said:

Feels like I'm loosing something in Affinity or PS is adding something within the algorithm.

If you place both files in AP with one set to difference in the Layers panel, do you see any visual differences?

[OldHickory30]

14 minutes ago, R C-R said:

If you place both files in AP with one set to difference in the Layers panel, do you see any visual differences?

When I compare the very large files side by side, seems the PS file has smoother details, better tonality. However haven't really compared many images.

[R C-R]

1 minute ago, OldHickory30 said:

When I compare the very large files side by side...

Did you try what I suggested using the Difference blend mode to compare them, one on top of the other? That is not the same as side by side.

[OldHickory30]

2 minutes ago, R C-R said:

Did you try what I suggested using the Difference blend mode to compare them, one on top of the other? That is not the same as side by side.

What I wanted  to  see whether there was any difference in size, without touching any adjustments coming straight from RAW, almost a 1 gig difference blew me away. Anyway I'll try your way as well. 

[R C-R]

14 minutes ago, OldHickory30 said:

What I wanted  to  see whether there was any difference in size, without touching any adjustments coming straight from RAW, almost a 1 gig difference blew me away.

What do you mean by "straight from RAW"? Are you trying to compare how the 2 apps export RAW files to TIFF or something else?

[OldHickory30]

Processed in RAW sent image as tiff to both apps.

[R C-R]

2 minutes ago, OldHickory30 said:

Processed in RAW sent image as tiff to both apps.

"Sent" means export, right? Since the 2 apps process RAW files differently (& have different options) it would not be surprising to see differences in the results.

[Ldina]

3 hours ago, OldHickory30 said:

Curious, why would there be such a  size difference after exporting from Photoshop, compared to Affinity? Seems that PS is always 40-90% larger. I processed two files 16bit w/ no extra layers, a tiff - native size. PS was 1.9gb and Affinity 1.08gb Thats almost a gig in difference. I've tried other configurations, same thing, PS is always much way larger with no compression. Feels like I'm loosing something in Affinity or PS is adding something within the algorithm. After 20+ years of using PS, I'm not a fan, but I am curious. 

It's been a while, but 16 bit files in PS can get pretty darn large very fast. In PS, each new layer increases file size substantially. Also, many operations in PS require you to add a new pixel layer and run a filter on that pixel layer. (My last work with PS was with CS6, so things may have changed since then). Affinity has Live Filters that can do some things differently, and those Live filter layers only have one Alpha Channel, with no RGB channels. I haven't spent time to investigate, but I assume that reduces file size also. I used to duplicate a pixel layer to do specialized sharpening in PS, then apply my sharpen routines to that duplicate pixel layer (which greatly increases file size). 

The best test is probably to export a flattened PNG or TIFF file of the same image from both PS and AP. If the pixel dimensions and export settings are the same, the file sizes should be pretty close in size, assuming the edits done in both PS and AP are close to identical. So, I don't think you are "losing" anything. I'm sure others are much more qualified to give technical explanations than I am.